Heat a wok until smoking and add two tablespoons of the groundnut oil, then fry the aubergine slices with a splash of water for 3-4 minutes, or until softened and golden-brown all over. Transfer to a plate and set aside.
Wipe away the excess oil from the wok, reheat and add the remaining groundnut oil. Heat until smoking. Stir fry the garlic, ginger and chilli for a few seconds, then add the minced pork. Stir fry for one minute, then add the rice wine or sherry. Cook for 3-4 minutes, or until browned, then add the chilli bean sauce and hot chicken stock. Return the aubergines to the wok and add the pak choi.
Season, to taste, with the vinegar and sesame oil and bring to the boil. Cook for 3-4 minutes, or until the pork is cooked through, then stir in the spring onions. Add the cornflour paste and stir until the liquid has thickened.
Spoon the fragrant pork and aubergines into a serving bowl and serve immediately.